In this study, the mineralogy of a novel resource of deep-sea sediments containing rare earth elements (REEs) was investigated, along with the leaching of REEs using hydrochloric acid. The results revealed that, apart from 62.0% of the Ce found in the Mn oxides, the other REEs in the deep-sea sediments mostly existed in hydroxyapatite mineral which can be easily decomposed via a hydrochloric acid leaching. An optimized REEs leaching percentage of 89.5% was achieved using 2.0 mol/L hydrochloric acid as the leaching agent, with a liquid-solid ratio of 4:1, at 60 °C for 30 min. However, Mn oxides remained stable during the leaching process, resulting in a low Ce leaching percentage of 30.7%. Under the optimized conditions, Mn oxides could be decomposed by adding 30% H2O2 as a reducing agent, leading to improved leaching percentages of Ce and REEs to 86.6% and 93.2%, respectively. The high leaching efficiency of REEs may further increase the utilization potential of this novel resource.

中文翻译：

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从新型深海沉积物来源中盐酸浸出稀土元素以及用 H2O2 还原的优势


在这项研究中，研究了一种含有稀土元素 （REE） 的新型深海沉积物资源的矿物学，以及使用盐酸浸出 REE。结果显示，除锰氧化物中 62.0% 的 Ce 外，深海沉积物中的其他稀土元素主要存在于羟基磷灰石矿物中，这些矿物很容易通过盐酸浸出分解。以 2.0 mol/L 盐酸为浸出剂，液固比为 4：1，在 60 °C 下 30 min 下，获得 89.5% 的优化稀土浸出率。然而，锰氧化物在浸出过程中保持稳定，导致 Ce 浸出率低至 30.7%。在优化条件下，添加 30% H2O2 作为还原剂可以分解 Mn 氧化物，导致 Ce 和 REEs 的浸出率分别提高到 86.6% 和 93.2%。稀土元素的高浸出效率可能会进一步提高这种新型资源的利用潜力。